Process for the separation of metallic sulfids from gangue and apparatus therefor.



L. BRADFORD. PROCESS FOR THE SEPARATION OF METALLIC SULFIDS FROM GANGUE AND APPARATUS THEREFOR. APPLICATION FILED MAR. 11, 1912.

LEQLQS Patented June 23,1914.

\N/TNEJSESL MW A R STAT PATENT LESLIE BEADIFGRD, 61E BRDKEN HILL, HE

MINERALS SEPARATIGN LIMITED, U15 LONDON,

BY DEESNE ASSIGNMENTS, T ENGLAND.

SOUTH WALES, AUSTRALIA, ASSIGNQR,

PRUGESS F03, THE SEPARATION OF METALLIC SULFIDF FROM G-ANG'UE AND ATEPABATUS THEREFUE.

Specification of Letters Patent.

Patented June 23 11 2914,

Application filed March 11, 1912. Serial No. ($533,005.

To all whom it may concern Be it known that if, LESLIE BRADFORD, a subject of the Yiig of Great Britain, residing at Broken ill in New South Wales, Australia, ess for the Separation of Metallic Sulfide from Gsngue and Apparatus Therefor, of which the following is s specification, reference being had therein to the sccompsny ing This invention has been devised to provide an economical and eiiicient process of treating metallic sulfide so as to separate them from the gsngue stun in which they are em hiaceri and the invention also includes a. combination of mechanical means to carry such trestinent into eiiect. lt is well known that sulliils can he recovered; from ores by several means, notably-y immersion in hot olntiozn when the sullitl particles tlost: by costing the y' gassed to vacuum, by which means gems films e2: float the oiled psi isles: by cleaning thosoughly the suliid pszticles and then looting some by filming" on the surface of Water: by vigorously agitating the ore with acid and. it very small proportion of oil or other :trothing agent or agents. anrl sin subse quently floating the suliid in a spitzkssten. Numerous other methods have also from time to time been proposed to bring about s recovery of sulfide from gsngue by means of flotation. Most of these methods fail when the ore is sl u'uecl or is in s fine state of division. llei'etofore, it has been gen erolly accepted that the only processes which are effective on this class. o materiel are those in which vigorous agitation is resortetl to, the essentials of such processes being the addition oils or other organic trothing proportions tillti admin rous beating in by mechanical means air, so that the ore. trothing agent sir solution iorni emulsion whichv when slloweo to repose in s ouiescent cond ion resul "n sepor' v A ,5: f n- N t W ,3; tion, toe shied potholes, rot ii & ogen moi included huhloles (together any evolved hi? the action oi the or; the eye} have invented an Improved Procoil anti subjecting i I flOtatlOD, sncl l there]? e do not innit 1st it is not neeessni floating to the to by reason of their aversion to become Wette the lower specific grsvity of the mass, surface tension, and other Vilrious efiects, While the gangue being thoroughly Wettecl is inert and sinks to the bottom. Moreoverso far as l sni swore inv all these frothing processes gnest stress is lsid on the beating in of air and the use of an organic frothing agent. '1? he nature and composition of the particular kind or kinds of trothing agents used hove formed the subject matter of numerous patents. l have found; thet'nnder certain conditions, flotation of the sulfide (Len be successfully produced hy the use st 2; dilute hot solution of sulfuric ooiol Without the of any hothing agent, sncl that it is not absolutely essential to best in any extraneous air, the ges generated by the action of the acid on the ore, if properly utilizeel, being quite suiticient to efiect s good flow. The admission sir anti steam undoubtedly assist in the "elf or w nout sir or Wi h or sllllClie li have found employ host to the some extent as is y adopte in the straight out ocitl flotation process. The degree to which the solution is heated prior to use is largely oepenclent on the nature of ore to be treated. it tenipeinture of M0 F. has been found; to be quite sufficient for most ores, although. s. lower legree of heat can he employed, and if the separation is not complete, the operation con he repeetecl. With other ores, temperatures very much lower than this have been found quite sufficient, While in some oases solutions at to operating Ul Without steam ordinary stino heiio teinpeiintures will no ll thetefore clo not yield; is l a innit niysei heat.

The main the ilotti mes-ins of in ous sgite' porticulsi degree of loo extraneous frothing agents such as the mineral or essential oils, the fatty acids, the phenols, aromatic acids, or resinous sub stances, the alcohols, ethers or vegetable acids, petroleum, tarry products, etc., the employment of such substances not being essential for the recovery of sulfids when my invention is employed. Various forms of inclosed agitating apparatus may be employed for the carrying out of the process.

In the accompanying drawing is shown a side elevation partly in section of a plant which I find effective. Referring thereto a is a mixer tank or box provided with a paddle b and means such as bevel gearing 0 and d for slowly revolving the shaft 6 so the contents of t e tank a will be mixed into the condition of a freely flowing pulp. Into this tank or box a the pulverized ore and feebly acidulated solution are delivered. Near the bottom of the said mixe box a is fixed an exit pipe 6 with a valve f to regulate the flow of the pulp to a throttled centrifugal pump 9 which in this case i used as the inclosed agitator. The runner shaft 9 of the ump 9 may be driven by the pulley g and supported in bearings g.

The intake pipe h to the pump has a small pipe 2' fixed in it for the addition of sulfuric acid in any required quantity. A steam air injector L is' tapped into the barrel of the pump g for the dual purpose of heating the acidulated ore pulp, and for the introduction of air if found necessary.

The exit pipe Z from the centrifugal pump is provided with a valve m for throttling the delivery of the pulp. The eflect of the throttling of the outlet of the. centrifugal pump 9 by the valve m is to cause the pulp to be thoroughly churned and agitated, thereby causing effective gasification and aeration of the metallic sulfid particles for their subsequent flotation. The thoroughly gassed pulp is delivered 'by the pump g into a spitzkasten n, where the separation takes place: the sulfids float to the top, by reason of the buoyancy of attached gas or air, and are allowed to flow away as concentrates by chute 0. while the residues sink to the bottom and escape through a continuously running plug hole 15. It will be readily understood that the requisite quantity of acid can be delivered by gravitation or otherwise into the intake pipe h to effect the reaction needed in the process and also that the steam and air entering in adjustable quantities will respectively heat and aerate the pulpy mixture to assist the separation aimed at. In operation the centrifugal pump fulfils the dual function of churning and delivering the pulpy mixture, the stop valves being so adjusted that the throttling by the valve m will cause the pulpy liqu1d to be frothed or aerated by the runner of the pump. The evolution of gas'within the pump chamber or the introduction ofair or other gas into the pump chamber, assures the presence in the pulp while it is being agitated by the runner of the pump of the necessary air or other gas forthe aeration or gasification of the pulp.

Having now described myinvention, what I claim as new and desire to secure by Letters Patent is 1. A process of concentratin ores, which consists in mixing the ore wlth water to form a flowing pulp, adding to the pulp suflicient acid to bring about the evolution of gas by chemical action of theacid, subjecting the pulp and evolved gas therein to violent agitation, and then flowin the agitated pulp away from the place 0 agitation and separating the floating material.

2. A process of concentrating ores, which consists in mixing the ore with water to form a flowing pulp, adding to the pulp suflicient acid to bring about the evolution of gas by chemical action of the acid and also introducing air into the pulp, subject- 7 ing the pulp and evolved gas and air therein to violent agitation and then flowing the agitated pulp away from the place of agitation and separating the floating material.

3. A process of concentrating ores, which consists in mixing the ore with slightly acidulated water to form a flowing pulp, adding to the pulp a further quantity of acid to bring about the evolution of gas by chemical action of the acid, subjecting the pulp and evolved gas therein to violent agitation, and then flowing the agitated pulp away from the place of agitation and separating the floating material.

4. A process of concentrating ores, which consists in mixing the ore with slightly acidulated water to form a flowing pulp, heating the pulp and adding to it a further quantity of acid to brin about the evolution of gas by chemical act1on of the acid, subjecting the pulp and evolved'gas therein to violent agitation, and then flowing the agitated pulp away from the place of agitation and separating the floating material. 5. A process of concentrating ores, which consists in mixing the ore with sli htly acidulated water to form a flowing pu heating the pulp and adding to it a further quantity of acid to bring about the evolution of gas by chemical action of the acid and also introducing air into the pulp, subjecting the pul and evolved gas and air therein to violent agitation, and then flowing the agitated pulp away from the place of agitation and separatingthe floating material. I

6. A process of concentrating ores, consists in mixing the ore with slightly acid ulated water to form a flowing pulp, adding to the pulp a further quantity of acid to bring about the evolution of gas by chemical action of the. acid, introducing air and steam to the closed chamber,

talented into the pulp, subjecting the heated pulp and evolved gas and air-therein to violent agitation, and then flowing the agitated pulp away from the place of agitation and separating the floating material.

7. In an ore separating apparatus, a combined pul agitator and pulp pump having a closed combined agitating and pump chamber, means for supplying an ore pulp and a gas to the closed chamber and means for conducting away the agitated pulp from the closed chamber.

S. In an ore separating apparatus, a combined pulp agitator and pulp pump having a closed combinedagitating and pump chamber, means for supplying an ore pulp to the closed chamber, and means for retarding the movement of the pulp through the closed chamber in opposition to the propulsive force f the pump agitation of the pulp within the pump.

9. An ore separating apparatus comprising, in combination, a combined pulp agitator-and pulp pump having a closed combined agitating and pump chamber, means for supplying an ore pulp and a gas to the closed chamber, and a separating vessel directly connected to the closed chamber for receiving the agitated pulp therefrom.

10. In an ore separating apparatus, a centrifugal device constituting a combined pul agitator and pulp pump and having a closed combined agitating and pump chamber, means for supplying an ore pulp and a gas and means for conducting away the agitated pulp from the closed chamber.

11. An ore separating apparatus comprising a centrifugal device constituting a combined pulp agitator and ulp pump and having a closed combined agitating and pump chamber, means for supplying an ore pulp and a gas to the closed chamber and an outlet therefrom, and an adjustable throttle for the outlet to 'retard delivery of the 'pulp from the closed chamber in opposition to the propulsive force of the pump.

12. An ore separating apparatus comprising, in combination, a centrifugal device constituting a combined pul agitator and pul pum including a closed combined agitating an pump chamber, means for supplying an'ore pulp and a gas to the closed 7 chamber, a separating vessel directly conthe body of liquid to eflect thorough nected with such chamber for receiving the agitated pulp therefrom, and an adjustable throttle interposed in such connection.

13. A process of concentrating ores which consists in mixing the ore with water to form a flowing pulp, flowing the ulp into a closed vessel and subjecting it t erein to violent agitation in the presence of a gas, flowing the agitated pulp away,from the place of agitation and directly into a body of liquid with continuation of the inclosure thereof until the pulp is delivered into the body of liquid, the pulp being delivered into the body of liquid below the liquid level and being in a substantially quiescent condition so that the gas in the pulp may exercise its flotative power, and separating the floating material from this body of liquid.

14. A process of concentrating ones which consists in mixing the ore with water to form a fiowing pulp, flowing the pulp into a closedvessel and subjecting it therein to violent a 'tation in the presence of a gas, flowing t e agitated pulp away from the place of agitation and directly into a body of liquid with continuation of the inclosure thereof until the pul is delivered into the body of liquid and restriction of the flow thereof, the pulp being delivered into the body of liquid below the liquid level and the body of liquid being in a substantially quiescent condition so that the' gas in the pulp may exercise its flotative power, and separating the floating material from the body of liquid.

15. An apparatus for concentrating ores comprising, in combination, a mixer, a centrifugal pump having its inlet in communication with the mixer, a throttle valve for restricting the discharge outlet of the (pump, means for introducing a fiotatiolrpro ucing substance into the mixture to be acted upon by the p and air into the mixture to be acted upon by the pump, and a separator communicatingwith the outlet of the pump.

In witness whereof, I have hereunto signed my name in the presence of two witnesses.

LESLIE BRADFORD.

Witnesses LEONARD W. BAKEWELL, J. B. JOHNSTON.

means for introducing steam I 

